


A Dark Past

by snobbleweb



Category: Supernatural
Genre: AU, Castiel's Past, F/M, Flashbacks, M/M, a lot of the same but some things changed, castiel did some bad stuff, castiel fell in love with a human, castiel's old vessel, dean is a little worried about castiel, fem!castiel in the past, ishim is a dick, not approved of heaven, pregnant female castiel gone wrong, sam is confused mostly
Language: English
Status: Completed
Published: 2017-07-17
Updated: 2017-07-17
Packaged: 2018-12-03 07:36:21
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,780
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11527590
Author URL: https://archiveofourown.org/users/snobbleweb/pseuds/snobbleweb
Summary: Castiel has a past that he doesn’t like to talk about much. One not erased by Naomi to serve as a lesson to him. One filled with sin, love for humans, an unborn nephilim, and a dead body.He’s kept it a secret from his new human friends hidden until Ishim brings up the past while searching for Benjamin’s killer. He might need to share his secrets in order to survive Lily Sunder's attacks.





	A Dark Past

**Author's Note:**

> This is my first supernatural fanfic and it was something that I thought up a couple days ago. I'll probably do more original works in the future we'll see.  
> Hope you like!

“You wait here.” The Winchesters were taken aback by Castiel’s words seeing as they had come all this way to help him.  
“Woah, wait, excuse me?” Dean asked, sounding a bit offended. Cas gave a bit of an eye roll and explained.  
“Ishim told me to come alone. He doesn’t like… humans,” Cas seemed casual about this fact, but the Winchesters, being, well, the Winchesters, were a little put off.  
“Sorry.” Cas said simply before turning to head into the cafe where he was meeting his old angel comrade.  
“Hey. No.” Dean said. “We came here to help you, so we don’t give a damn if he doesn’t like us.” Dean said, pushing past Castiel and walking in. Cas gave an annoyed sigh and gave Sam a look, who just shrugged and headed in after him.   
Cas followed them and led them to a table where a man sat and a woman lingered near by. They both eyed the humans with Castiel with disgust.  
“I thought I told you to come alone.” Ishim said casually, a hint of distaste in his words. He picked up a sugar packet and poured it into his coffee.   
“These are my… Friends… They are here to help me find Benjamin’s killer.” Cas said, his voice lowered a little in submission, he knew he probably shouldn’t have brought humans with him. The two angels stayed quiet, Ishim keeping himself busy by adding more sugar to his coffee. Cas cleared his throat a little.  
“I see you’ve kept your vessels… All this time.” Cas said rather friendly.  
“We are not careless.” The female angel practically hissed. Dean looked up at her in anger but kept quiet. He then turned his attention to Ishim. Oh they are just asking to be stabbed. He thought.  
“How about a little coffee with that sugar.” Dean remarked.  
Ishim gave him an amused look before turning back to Castiel.  
“So how have you been? After leading your own battalion then betraying heaven and killing thousands of angels, we haven’t heard or seen from you much.” Ishim snapped sarcastically. Dean bit his lip, wanting so much to punch the angel in the face. Cas simply looked down a bit nervously, not daring to answer. Dean looked over at Cas, noticing his dejected mood.  
“But of course now you’re seen as a hero,” He said. “I guess you didn’t need me to pull you up from nothing this time.”  
Sam gave a quick glance at Cas, a bit confused. Dean was still seething next to him.   
“You always choose them, don’t you. No matter how many times we have to drill it into that rebellious little mind of yours.” He gave a gesture to his head like he was holding a drill.  
“I still care about the angels,” Cas said, only slightly confident with himself at this point.  
“Oh, yes that’s why you're here. To avenge the death of Benjamin. If only you’d shown that kind of care to the angels in your battalion. You know, the ones you killed.” Ishim remarked.  
“Why don’t we just focus on Benjamin, I didn’t really come specifically to be insulted.” Cas said, a little angry. Dean smirked a little, glad to see Cas finally standing up for himself.   
Ishim stared at him for a moment, then turned to the other angel.  
“Mirabel, why don’t you check outside to see if they were followed.”   
Ishim watched her leave then turned to the Winchesters.  
“You know when Castiel served under me, he was a soldier.. A warrior… An angel’s angel.” Sam and Dean were giving him annoyed looks from across the table.  
“You’ve fallen quite far Castiel… I’d hoped this wouldn’t happen again after the last time.”  
Sam looked at Dean for a moment before looking back at Ishim, feeling lost. Dean simply glared.  
“All you got now is a couple of poorly trained monkeys,”  
“Oh, well you can go to hell,” Dean replied, clearly offended. Ishim smirked.  
“Dean, just leave it” Cas sighed.  
Same piped up. “What? No. We’re not gonna leave it. He keeps insulting you-”  
“This is not about me, this is about Benjamin,” Cas cut him off, and turned once again to Ishim.  
“Exactly, now. Why don’t we go discuss this in a place a little more private, since you decided to bring a couple more.. People..Along.” He got up and pulled out some cash. “I’ll go get Mirabel.”  
He gave one last long cold stare at Castiel then flung the money in front of Dean. “Why don’t you get some pie?” He glowered then walked out.   
They all sat there for a second, both the Winchesters in shock.  
“Wow.” Sam said, raising his eyebrows and switching to the other side of the booth.  
“Hell of a friend, Cas… What was all that he was talking about? Am I the only one?” Sam questioned, but Dean popped in. “Why the hell would you let him talk to you like that?” Sam seemed a little upset his question got ignored, but he had the same concern. Cas looked a little down.  
“If Ishim… Can help me find Banjamin’s killer… I have to,”   
“Okay, yeah, I get that we need Super Dick there, but… Come on,” Dean turned to him, concerned. “He acted like you’ve done something like… This before.”  
“Were you always like them? Before you um rebelled?” Sam asked. Cas seemed uncomfortable.  
“I, Uh, That’s not really relevant for right now… Maybe later. We should follow him.” Cas said, getting up and encouraging Dean to do the same and let him out of the booth. Cas left the cafe rather quickly, leaving Sam and Dean to stand there for a moment in silence.   
Cas was waiting for them outside as they went to find Mirabel and Ishim.  
They came upon a woman holding a knife near Ishim’s throat as he was trying to hold her back. Cas quickly unwielded his blade and attacked her, slicing into her side and sending her to the ground. Dean and Sam pulled out their guns as the woman looked up at Cas, quickly frowning.  
“I… Know you, “ Cas whispered before she turned to the Winchesters.  
“I don’t want to hurt any humans, let me finish what I started.” She got up, holding her side and wincing.  
“Yeah, not gonna happen Patches.” Dean said, cocking his gun and pointing it at her.  
The woman quickly saw the danger and held up her hand, blasting light from it and blinding them. When the light dissipated she was in her car, turning it on and quickly driving away.   
“Hey, I can’t see, did you get a plate?” Dean stammered, grasping onto Sam’s shoulder for balance. The car quickly zoomed off into the darkness but Sam was watching closely.  
“Yeah.”  
“Ishim,” Cas said, hurrying to Ishim and helping him up. “Let’s get to that safe house you mentioned.  
They all got to the Impala and Ishim led them to a large abandoned building in the middle of a field.   
Cas set Ishim down on a couch and tried to check on his wounds. He grunted and pulled his shirt down, trying to support himself. Cas sighed and sat down next to him.  
“Ishim, how is she still alive?” He said, obviously very anxious for an answer. Sam looked at them both, stunned. “Wait, you know her?”  
“Yes,” Cas quickly replied. Ishim glared at him. “You don’t owe them an explanation,”  
“Ishim, they are here to help, they might as well know, they could help us find her,” Cas explained, before Ishim grunted and looked away.  
Cas took that as permission and turned to his friends. “Before the Apocalypse, angels rarely came to earth, except in very special circumstances,” The Winchesters listened intently. “Many years ago, an angel named Akobel came to earth and fell in love with a human, they had a Nephilim together.”   
“Wait, a Nephilim?” Sam asked. Cas gave an anxious glance at Ishim, who was staring at him intensely. “An abomination… A child of an… Angel and a…. Human.” Cas shifted a little bit, which this and his speech pattern didn’t go unnoticed by the Winchesters. They both wondered why this was such a delicate topic.   
“And we had to kill it.” Ishim continued for him, still staring at Castiel. Sam and Dean both looked put off by this new information.  
“So who’s the patched chick?” Dean asked, turning to Cas.  
“She was the mother of the child…” Cas answered quietly. There was a moment of silence.  
“So Cas.. You uh..” Sam said, wiping his hands against his face.  
“Oh don’t worry, Cas didn’t have a direct part in this. We simply showed him what was needed to be done. A lesson, you could say.” Ishim said, a little tantalizing in his words.  
“You didn’t have to bring me along…” Cas spurted out under his breath, obviously a little caught up in his emotions.   
“NO, Castiel. You see this is what happens when angels get involved with humans. You should know. We needed you to learn the job of an angel!” Ishim brought himself upward rather quickly and grabbed onto Castiel’s coat, catching him off guard. Dean quickly rose from his chair, ready to defend. “And now that wench is back for her revenge, all because an angel couldn’t listen to the rules.” Cas looked farther down.  
“But how is she alive, Ishim, you’re the one who went in there…” Cas said, suddenly finding some ground and looking up again.   
“I took mercy on her,” Ishim replied.   
“How is she still alive though? What is she like 100 now?” Sam asked.  
“More,” Cas added.  
“I know what she’s up to, she made some kind of… Demonic pact, keeps her young, keeps her strong… and immune to our powers.”  
“Alright, we’ll find her. Me and Sam. Since she doesn’t care about us we can figure out her deal and maybe get her to back off.”  
“I doubt she will…” Cas’ voice wandered. “And she won’t back off until she’s killed all the angels involved in her child’s death,”  
“Yeah, well we’re gonna try anyway. Maybe we can convince her that you’ve changed… Or that you were never like that.” Dean shot a glance at Ishim before getting up.  
“Alright, but be careful.”  
“Of course,” Dean replied and he and Sam headed out.

Cut to Lily Sunder trying to kill Ishim after finding him in the warehouse  
Dean and Sam were currently imobile, watching helplessly as Lily Sunder attempted to kill Ishim and Castiel. Ishim was giving a speech about how he loved her and how she betrayed him. Castiel was behind him, taking in Ishim’s lies. He now knew that Ishim had killed an innocent human child and Akobel all because he felt betrayed that Lily had chosen another. Castiel also remembered… Before.

Castiel could feel a deep pain in her lower abdomen, it was wrenching, causing her to fall to her knees. She could see blood on the floor, and her hand raised to her mouth to stifle a sob. She fell forward and caught herself on the floor. Her hands touching the hot blood seeping around her, she involuntarily rose her head to look once again at the man before her. His eyes burned out and his gut sliced open. She finally collapsed, holding onto her gut and staring up at the figures before her. In front was Ishim, looking at her with a slight smile on his face. The others showed expressions of disapproval. 

He flashed back into the present, feeling the pain well inside of him once again. He hadn’t allow it overcome it until now when it seemed Ishim didn’t deserve his respect. He hadn’t done his duty. He had no right to claim to always follow the ways of heaven.  
Cas gripped his angel blade tight before lunging forward. He could feel the blood on his hands even before the light shot out of Ishim’s eyes, and angels scream could be faintly heard before he let the angel fall to the floor. Tears were now silently falling from his face as he stared at the ashy outline of wings etch from Ishim’s body and spread across the floor. Lily Sunder looked down in shock then up at Castiel. She still had her weapon in hand but made no move to use it.  
All she could get out was a faint “why?” as Castiel dropped his blade and walked closer to her. Dean and Sam were rising from their spot on the floor only to see Cas walk up to Lily and embrace her in a hug. They both had shocked looks on their faces as the scene unfolded in front of them.  
Cas grasped the woman tight and started to whisper in her ear. “I understand… I’m so sorry... So sorry…” Lily pushed him away, confused.  
“I don’t understand.” She simply said, hoping for an explanation.  
“You and us both,” Dean said, walking up next to them, accompanied by Sam.  
Cas lifted a finger to Lily’s forehead and in a flash she and him were suddenly somewhere else. She felt like she was floating, watching a scene in front of her as if she wasn’t even there.   
The first place they were was in a book shop, and they stood near the wall as they watched a young woman come up to the counter where a young man was smiling ear to ear to see her. She leaned over and pulled him into a kiss, then smiled awkwardly and blushing as she pulled away. She put a hand to her forehead as if she was listening to something then appeared quite frightened. “I’ve got to go,” She said and disappeared with only the faint sound of wings flapping.  
Cas and Lily suddenly went somewhere else, as if following the girl who had just disappeared. They were in heaven, watching as the girl stood before mostly unfamiliar angels, Ishim, Benjamin and Mirabel standing among them. Naomi confronted her, and Cas and Lily could only barely hear as she was accused of lying with a human, for they sensed the life starting to form in her human womb. The girl fled and they watched as she and the man kept on the run from the angels for months before they finally stopped in a small house. The angels had caught up to them. One standing by Naomi walked up with an angel blade and sliced it across the human man’s stomach, sending him to the floor. The girl angel screamed and knelt next to him, frantically trying to heal him. The angels in the room were blocking it. The angel who had sliced him, bent down and placed a hand on his head. The girl had hope that he was trying to heal him but light shot from his eyes as he screamed. He was dead within seconds, his eyes burned from their sockets. The girl watched in horror and could only sit there for a moment before she moved again. She got up, tears in her eyes and she pulled out an angel blade, ready to take on the group. Naomi snapped her fingers and the girl doubled over in pain. She didn’t last long on her feet and ended up on the floor. Ishim stepped forward, talking with Naomi.   
“I don’t see the point in erasing her memory, why don’t we just teach her a lesson.” He suggested and Naomi nodded. In a flash they were gone, leaving only the man's body on the ground and the remnants of blood from the rebel angel. Cas and Lily flashed back into the present. Seeming as no time had passed at all, but they stood there, breathless. Lily had started to cry and stood there, staring in shock at Castiel.  
“Was…. Was that you?” She stammered. Dean and Sam looked at her confused. “What just happened?” Dean asked. Cas nodded to Lily and she dropped her weapon.  
“Did you… Did you’re…. Die?” She could barely get the words out and Cas nodded again. She looked down at Ishim with a blank expression.  
“I’m so sorry,” She said softly. Cas grabbed her hand. “No I should be sorry, I should never have let them do that to someone else.” They shared a silent moment, staring at each other.  
“Hey could someone please explain what the hell is happening?” Dean asked louder. Cas looked at him. “I uh… Showed her my past,” Dean’s eyebrow raised.   
“Something we don’t know about?” He asked. Cas nodded, he didn’t know what to say.  
“I’ll tell you some other time.” Cas said, placing a hand on Dean’s shoulder then walking away.


End file.
